Try your zoom controls.

<Control> + (plus) enlarge <Control> - (minus) reduce <Control> 0 (zero) restore

FredMcD said

Try your zoom controls. <Control> + (plus) enlarge <Control> - (minus) reduce <Control> 0 (zero) restore

Thanks for your answer, but this advice can not help :). In my case problem in popup window, not web-page (there is no dev. version)

You may have a corrupt xulstore.json file. https://support.mozilla.org/en-US/kb/changes-toolbars-and-window-sizes-are-not-saved

Thanks for your answer, but problem is easier. If I set 11pt for message window, the setting page display correctly. It's just a problem with 12pt and 1366x768 resolution. Most of apps work perfectly with this font size, firefox setting windows is an exception.

Do you have things in hand, or would you like me to call for more help?

Does that window becomes that high that it exceed your screen height and extends beyond the screen? It is possible that the position of those element are specified as em values or otherwise are dependent of font sizes. If that is the case then it might be possible to override such rules via the userChrome.css file and possibly set a max-height to affected windows.

• DOM Inspector: https://addons.mozilla.org/firefox/addon/dom-inspector-6622/
• https://developer.mozilla.org/DOM_Inspector/Introduction_to_DOM_Inspector

The customization files userChrome.css (user interface) and userContent.css (websites) are located in the chrome folder in the Firefox profile folder.

• http://kb.mozillazine.org/Editing_configuration

Thanks for answer, but it can not help. I tried change options windows, using

1. BrowserPreferences{

height:/*whatever em, rem*/ !important; max-height: 40rem !important; } ___________________________ The problem was in min-height, it was 46 em, with 42 rem everything is OK...